This invention relates to abrasive tools (abrasive films) suited for use in polishing, lapping, texturing, or other similar finish of precision machinery, devices, and parts, e.g., magnetic heads, hard disks, floppy heads, floppy disks, ceramic articles, plastic items, and jewels.
Abrasive films currently in use comprise a plastic film backing and an abrasive coat or layer of abrasive-dispersed coating material formed continuously or discontinuously over the backing. The abrasives employed include diamonds, alumina, silicon carbide, iron oxide, and chromium oxide.
High precision grinding requires an abrasive of fine grain size. Generally, the smaller the particle diameter of the abrasive the greater the difficulties involved in uniformly dispersing the abrasive in a resin because increased surface energy makes the particles easier to agglomerate. The grains, when applied in the agglomerated state, can scratch the workpiece or shorten the abrasive film life due to breaking down from the backing or other deficiency. The surface roughness of the coat decreases in proportion to the grain size, until the surface becomes nearly mirror smooth. This can increase the friction between the surface and the workpiece during grinding to such an extent that deposition or fusing of the binder resin occurs or the abrasive film life is shortened by loading owing to difficulties in removing the chips resulting from grinding.